During surgery, blood vessels often have to be severed and sealed after severing to prevent bleeding. Such sealing of blood vessels is normally carried out with a “thread ligature” in which both ends of the vessel are ligated with a thread before the blood vessel is severed therebetween.
In the case of more recent methods, a high-frequency coagulation is carried out with surgical pincers or forceps, in the case of which a minimum contact force is exerted on the vessel walls with two mutually opposite surface electrodes, while the high-frequency (HF) energy input via the surface electrodes ensures heating of the vessel material. Coagulation and a bonding of the mutually opposite vessel walls are thus brought about, with the vessel being “sealed.” Such coagulation instruments are known, for example, from DE 42 42 143 C2 or EP 0 997 108 A2.
While smaller vessels (under 1 mm diameter) are sealed by their inherent contraction process, the sealing of larger vessels is problematic since the sealing points must also be able to withstand the maximum internal vessel pressure of the circulatory system. This problem increases with the size (the diameter) of the blood vessel.